Fix off-by-1 error in pointing key update

This fixes a fairly egregious error in how the pointing update works. The pointing table values are the CCD pixel coordinates and are 0-based while FITS WCS is 1-based. Thus, we need to add 1 when updating the CRPIX values with the X0,Y0 keys. See section 2.2 of the JSOC keywords doc: http://jsoc.stanford.edu/~jsoc/keywords/AIA/AIA02840_K_AIA-SDO_FITS_Keyword_Document.pdf

This also fixes an issue where the pointing values in the table were being assigned a unit of arcsec instead of pixel. This had no impact on the pointing update though since the units were stripped in the end anyway.